Clinical manifestations.....:

Clinical manifestations..... Strains of Sh. dysenteriae 1  haemolytic uraemic syndrome It is associated with complement activation and DIC in children Death from bacillary dysentery  extremes of life or with debilitating condition 1/22/2013 18 Shigella

PowerPoint Presentation:

AT RISK GROUPS Children in day care centers International travelers Patients with HIV infection People living with inadequate water supply Persons in prisons & military camps 1/22/2013 19 Shigella

The Shiga Toxin :

The Shiga Toxin Expression of Shiga toxin has been shown to be iron regulated  toxin production increasing under conditions of iron restriction The toxin has a molecular weight of 68,000 da A subunit  responsible for the toxic action of the protein B subunit  responsible for binding to a specific cell type globotriosylceramide Gb 3 1/22/2013 Shigella 40

Host Defence:

Host Defence Shigellosis childhood disease The incidence decreases drastically in the indigenous population over 5 years of age Studies in North American adults indicate prior infection with Sh. flexneri protects against reinfection (70% efficacy) 1/22/2013 Shigella 50

PowerPoint Presentation:

Colonies circular, convex, colorless, moderately translucent smooth surface, and entire edges Small tangled hair-like projections can sometimes be seen at one or more points on the periphery of the colony 1/22/2013 70 Shigella

ELISA:

Serotyping :

Serotyping Should be performed from a non–sugar-containing medium, such as 5% sheep blood agar Preliminary serologic grouping of Shigella spp. Is also performed using commercially available polyvalent somatic (“O”) antisera designated A, B, C, and D Subtyping of Shigella spp. beyond the groups A, B, and C performed by reference laboratories 1/22/2013 81 Shigella

TREATMENT:

TREATMENT Shigella dysentery  Sh. Sonnei  do not require antibiotic therapy Maintenance of good nutrition Maintenance of hydration by use of oral rehydration salt solution Treatment with a suitable antibiotic  very young, the aged or the debilitated 1/22/2013 85 Shigella

ORS:

Shigellosis :

Shigellosis Shigellosis a major problem in tropical areas of the developing world  shigellosis is endemic 5 million cases require hospital treatment and 600000 die every year Young children are particularly vulnerable 1/22/2013 88 Shigella

Sources and spread:

Sources and spread Highly contagious and is usually spread by the faecal-oral route Contamination of foods  those consumed raw 1/22/2013 89 Shigella

EPIDEMIOLOGY:

EPIDEMIOLOGY During the twentieth century, infections due to S. dysenteriae 1 and S. boydii declined and strains of S. sonnei became dominant in the UK and other European countries In England and Wales more than 16000 cases of Sonnei dysentery were recorded in 1992. 1/22/2013 90 Shigella

PowerPoint Presentation:

The incidence then declined steadily to an annual average of fewer than 1000 notified cases between 1998 and 2004 1/22/2013 Shigella 91

PowerPoint Presentation:

When later exposed to LPS Shigella bacterial cell  developments of IgG and IgA When infected with live homologous organisms  80-100% survival in all vaccinated groups Negligible survival in control groups 1/22/2013 97 Shigella